To avoid a potential hazard of a vehicle inadvertently and/or accidentally moving away from a loading dock during loading or unloading thereof, it has been customary in the past to utilize either a plurality of blocks which are wedged under certain wheels of the vehicle and in many instances are ineffective in restraining movement of the vehicle or to utilize a complex mechanism which is costly to install on a dock facility and frequently requires substantial structural modification thereof and oftentimes is awkward, difficult and time-consuming to engage and disengage from the vehicle parked at the dock.